snmp_pdu.c

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    struct snmp_pdu *PDU)
{
    u_char *bufp;

#ifdef DEBUG_PDU_ENCODE
    snmplib_debug(8, "PDU: Encoding %d\n", PDU->command);
#endif

    /* ASN.1 Header */
    switch (PDU->command) {

/**********************************************************************/

    case TRP_REQ_MSG:

	/* SNMPv1 Trap */

	/* enterprise */
	bufp = asn_build_objid(DestBuf, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OBJECT_ID),
	    (oid *) PDU->enterprise, PDU->enterprise_length);
	if (bufp == NULL)
	    return (NULL);

	/* agent-addr */
	bufp = asn_build_string(bufp, DestBufLen,
	    (u_char) (SMI_IPADDRESS | ASN_PRIMITIVE),
	    (u_char *) & PDU->agent_addr.sin_addr.s_addr,
	    sizeof(PDU->agent_addr.sin_addr.s_addr));
	if (bufp == NULL)
	    return (NULL);

	/* generic trap */
	bufp = asn_build_int(bufp, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    (int *) &PDU->trap_type, sizeof(PDU->trap_type));
	if (bufp == NULL)
	    return (NULL);

	/* specific trap */
	bufp = asn_build_int(bufp, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    (int *) &PDU->specific_type,
	    sizeof(PDU->specific_type));
	if (bufp == NULL)
	    return (NULL);

	/* timestamp */
	bufp = asn_build_unsigned_int(bufp, DestBufLen,
	    (u_char) (SMI_TIMETICKS | ASN_PRIMITIVE),
	    &PDU->time, sizeof(PDU->time));
	if (bufp == NULL)
	    return (NULL);
	break;

/**********************************************************************/

    case SNMP_PDU_GETBULK:

	/* SNMPv2 Bulk Request */

	/* request id */
	bufp = asn_build_int(DestBuf, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    &PDU->reqid, sizeof(PDU->reqid));
	if (bufp == NULL)
	    return (NULL);

	/* non-repeaters */
	bufp = asn_build_int(bufp, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    &PDU->non_repeaters,
	    sizeof(PDU->non_repeaters));
	if (bufp == NULL)
	    return (NULL);

	/* max-repetitions */
	bufp = asn_build_int(bufp, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    &PDU->max_repetitions,
	    sizeof(PDU->max_repetitions));
	if (bufp == NULL)
	    return (NULL);
	break;

/**********************************************************************/

    default:

	/* Normal PDU Encoding */

	/* request id */
#ifdef DEBUG_PDU_ENCODE
	snmplib_debug(8, "PDU: Request ID %d (0x%x)\n", PDU->reqid, DestBuf);
#endif
	bufp = asn_build_int(DestBuf, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    &PDU->reqid, sizeof(PDU->reqid));
	if (bufp == NULL)
	    return (NULL);

	/* error status */
#ifdef DEBUG_PDU_ENCODE
	snmplib_debug(8, "PDU: Error Status %d (0x%x)\n", PDU->errstat, bufp);
#endif
	bufp = asn_build_int(bufp, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    &PDU->errstat, sizeof(PDU->errstat));
	if (bufp == NULL)
	    return (NULL);

	/* error index */
#ifdef DEBUG_PDU_ENCODE
	snmplib_debug(8, "PDU: Error index %d (0x%x)\n", PDU->errindex, bufp);
#endif
	bufp = asn_build_int(bufp, DestBufLen,
	    (u_char) (ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
	    &PDU->errindex, sizeof(PDU->errindex));
	if (bufp == NULL)
	    return (NULL);
	break;
    }				/* End of encoding */

    return (bufp);
}

/**********************************************************************/

/* Decodes PDU from Packet into PDU.
 *
 * Returns a pointer to the next byte of the packet, which is where the
 * Variable Bindings start.
 */
u_char *
snmp_pdu_decode(u_char * Packet,	/* data */
    int *Length,		/* &length */
    struct snmp_pdu * PDU)
{				/* pdu */
    u_char *bufp;
    u_char PDUType;
    int four;
    u_char ASNType;
    oid objid[MAX_NAME_LEN];

    bufp = asn_parse_header(Packet, Length, &PDUType);
    if (bufp == NULL)
	ASN_PARSE_ERROR(NULL);

#ifdef DEBUG_PDU_DECODE
    snmplib_debug(8, "PDU Type: %d\n", PDUType);
#endif

    PDU->command = PDUType;
    switch (PDUType) {

    case TRP_REQ_MSG:

	/* SNMPv1 Trap Message */

	/* enterprise */
	PDU->enterprise_length = MAX_NAME_LEN;
	bufp = asn_parse_objid(bufp, Length,
	    &ASNType, objid, &PDU->enterprise_length);
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

	PDU->enterprise = (oid *) xmalloc(PDU->enterprise_length * sizeof(oid));
	if (PDU->enterprise == NULL) {
	    snmp_set_api_error(SNMPERR_OS_ERR);
	    return (NULL);
	}
	xmemcpy((char *) PDU->enterprise, (char *) objid,
	    PDU->enterprise_length * sizeof(oid));

	/* Agent-addr */
	four = 4;
	bufp = asn_parse_string(bufp, Length,
	    &ASNType,
	    (u_char *) & PDU->agent_addr.sin_addr.s_addr,
	    &four);
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

	/* Generic trap */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    (int *) &PDU->trap_type,
	    sizeof(PDU->trap_type));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

	/* Specific Trap */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    (int *) &PDU->specific_type,
	    sizeof(PDU->specific_type));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

	/* Timestamp */
	bufp = asn_parse_unsigned_int(bufp, Length,
	    &ASNType,
	    &PDU->time, sizeof(PDU->time));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);
	break;

/**********************************************************************/

    case SNMP_PDU_GETBULK:

	/* SNMPv2 Bulk Request */

	/* request id */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    &PDU->reqid, sizeof(PDU->reqid));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

	/* non-repeaters */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    &PDU->non_repeaters, sizeof(PDU->non_repeaters));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

	/* max-repetitions */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    &PDU->max_repetitions, sizeof(PDU->max_repetitions));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

	break;
/**********************************************************************/

    default:

	/* Normal PDU Encoding */

	/* request id */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    &PDU->reqid, sizeof(PDU->reqid));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

#ifdef DEBUG_PDU_DECODE
	snmplib_debug(8, "PDU Request ID: %d\n", PDU->reqid);
#endif

	/* error status */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    &PDU->errstat, sizeof(PDU->errstat));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

#ifdef DEBUG_PDU_DECODE
	snmplib_debug(8, "PDU Error Status: %d\n", PDU->errstat);
#endif

	/* error index */
	bufp = asn_parse_int(bufp, Length,
	    &ASNType,
	    &PDU->errindex, sizeof(PDU->errindex));
	if (bufp == NULL)
	    ASN_PARSE_ERROR(NULL);

#ifdef DEBUG_PDU_DECODE
	snmplib_debug(8, "PDU Error Index: %d\n", PDU->errindex);
#endif

	break;
    }

    return (bufp);
}


char *
snmp_pdu_type(struct snmp_pdu *PDU)
{
    switch (PDU->command) {
    case SNMP_PDU_GET:
	return ("GET");
	break;
    case SNMP_PDU_GETNEXT:
	return ("GETNEXT");
	break;
    case SNMP_PDU_RESPONSE:
	return ("RESPONSE");
	break;
    case SNMP_PDU_SET:
	return ("SET");
	break;
    case SNMP_PDU_GETBULK:
	return ("GETBULK");
	break;
    case SNMP_PDU_INFORM:
	return ("INFORM");
	break;
    case SNMP_PDU_V2TRAP:
	return ("V2TRAP");
	break;
    case SNMP_PDU_REPORT:
	return ("REPORT");
	break;

    case TRP_REQ_MSG:
	return ("V1TRAP");
	break;
    default:
	return ("Unknown");
	break;
    }
}

/*
 * Add a null variable with the requested name to the end of the list of
 * variables for this pdu.
 */
void 
snmp_add_null_var(struct snmp_pdu *pdu, oid * name, int name_length)
{
    struct variable_list *vars;
    struct variable_list *ptr;

    vars = snmp_var_new(name, name_length);
    if (vars == NULL) {
	perror("snmp_add_null_var:xmalloc");
	return;
    }
    if (pdu->variables == NULL) {
	pdu->variables = vars;
    } else {

	/* Insert at the end */
	for (ptr = pdu->variables;
	    ptr->next_variable;
	    ptr = ptr->next_variable)
	    /*EXIT */ ;
	ptr->next_variable = vars;
    }

    return;
}